quadrax

Intellijel Quadrax

Quad function generator with cascading and CV control

14 HP Eurorack module

The Intellijel Quadrax is a four-channel envelope generator and LFO with extensive modulation capabilities. Each channel can independently operate in four modes: AD (attack-decay), ASR (attack-sustain-release), Cycle (free-running LFO), and Burst (burst generator). Rise and fall times are independently adjustable from sub-millisecond to ~30 seconds, with selectable curve shapes (exponential, linear, logarithmic). Four CV inputs with attenuverters allow voltage control of timing parameters. Channels can be linked/cascaded for complex multi-stage envelopes. Multi-color LEDs indicate mode and output level for each channel. The optional Qx expander adds additional CV routing, end-of-cycle outputs, and quadrature LFO capabilities. Quadrax is one of the most versatile function generators available, equally capable as a snappy percussion envelope, slow ambient LFO, or complex multi-stage modulation source. 14HP.

Features

  • 4 independent function generator channels
  • Assignable cascading between channels
  • Voltage-controlled rise/fall times and curve shape
  • EOC and EOF trigger outputs per channel
  • Quadrax Expander adds CV inputs for all parameters
  • Internal clock for Cycle mode
  • Simultaneous use of different modes across channels

Controls & Jacks (36)

  • LEVEL— Master output level for Channel 4. Scales the output voltage.
  • FALL 2— Decay/fall time for Channel 2. Same behavior as FALL 1.
  • Shape 2— Curve shape for Channel 2. Same behavior as Shape 1.
  • FALL 4— Decay/fall time for Channel 4.
  • RISE 4— Attack/rise time for Channel 4.
  • FALL 3— Decay/fall time for Channel 3.
  • Shape 4— Curve shape for Channel 4.
  • RISE 3— Attack/rise time for Channel 3.
  • FALL 1— Decay/fall time for Channel 1. Sets how quickly the output falls from peak. In Cycle mode, sets the second half of the LFO period.
  • RISE 1— Attack/rise time for Channel 1. Sets how quickly the output rises to peak level. Range from sub-millisecond to ~30 seconds.
  • RISE 2— Attack/rise time for Channel 2. Same range and behavior as RISE 1.
  • Mode 3— Selects function generator mode for Channel 3.
  • Mode 4— Selects function generator mode for Channel 4.
  • Shape 3— Curve shape for Channel 3.
  • Mode 2— Selects function generator mode for Channel 2. Same options as Mode 1.
  • Shape 1— Curve shape for Channel 1. CCW = exponential (snappy), center = linear, CW = logarithmic (smooth). Affects both rise and fall segments.
  • OUT 2— Envelope/function output for Channel 2.
  • OUT 4— Envelope/function output for Channel 4.
  • Mode 1— Selects function generator mode for Channel 1. Cycles through: AD (attack-decay), AHR (attack-hold-release), Cycle (free-running LFO), Rise,
  • CV D— CV input for Channel 4.
  • CV B In— CV input for Channel 2. Modulates Rise or Fall time, scaled by CV 2 attenuverter.
  • CV 2— Attenuverter for Channel 2's CV input.
  • OUT 1— Envelope/function output for Channel 1. 0-8V unipolar.
  • CV C In— CV input for Channel 3. Scaled by CV 3 attenuverter.
  • CV A— CV input for Channel 1. Modulates Rise or Fall time, scaled by CV 1 attenuverter.
  • OUT 3— Envelope/function output for Channel 3.
  • TRIG 2— Trigger/gate input for Channel 2.
  • TRIG 1— Trigger/gate input for Channel 1. Rising edge starts the envelope. Gate high sustains in AHR mode.
  • CV 1— Attenuverter for Channel 1's CV input. Scales incoming CV that modulates Rise or Fall time depending on the Qx expander assignment.
  • TRIG 3— Trigger/gate input for Channel 3.
  • TRIG 4— Trigger/gate input for Channel 4.
  • CV 3— Attenuverter for Channel 3's CV input.
  • Channel 2— Indicates Channel 2 output level and mode.
  • Channel 1— Indicates Channel 1 output level and mode by color. Brightness tracks the CV output.
  • Channel 4— Indicates Channel 4 output level and mode.
  • Channel 3— Indicates Channel 3 output level and mode.

How-To Guides

  • Set Up a Basic AD Envelope
  • Create a Sustained AHR Envelope for Held Notes
  • Set Up a Free-Running LFO
  • Create Burst/Ratchet Triggers
  • Build a Four-Channel Drum Envelope Kit
  • Add CV Control to Envelope Timing
  • Cross-Modulate an Envelope with an LFO
  • Sync an LFO to External Clock

Explore the interactive Quadrax panel on BleepDex — tap any control to learn what it does.

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